Henne
California — Napa County — Angwin Stream
Location
| State | California |
| County | Napa |
| River | Angwin Stream |
| Coordinates | 38.58650, -122.46280 |
Physical Characteristics
| NID Height | 49 ft |
| Dam Height | 49 ft |
| Dam Length | 470 ft |
| NID Storage | 109 acre-ft |
| Max Storage | 109 acre-ft |
| Surface Area | 9 acres |
Safety Classification
| Hazard Potential | High |
| Condition Assessment | Satisfactory |
| EAP Status | Yes |
| Last Inspection | September 11, 2025 |
| Inspection Frequency | 1 |
Dam Information
| Year Completed | 1959 |
| Primary Purpose | Water Supply |
| Dam Type | Earth |
| Owner Type | Private |
| Owner | Howell Mountain Mutual Water Company |
Location Map
About This Dam Record
Dam safety data is maintained by the Army Corps of Engineers National Inventory of Dams (NID). High-hazard dams are those where failure could cause loss of life or major property damage downstream.